PLC (Power Line carrier Communication) refers to a communication mode in which power line is used as an information transmission medium and the signals are transferred between nodes in a power grid using a carrier modulation technology. The PLC technology is widely used in many applications such as remote meter reading, smart home appliances, etc.
The power line is a complex communication system with large signal attenuation, small line impedance, various noise sources and strong interference. For a same power line section, the transmission property varies because of different components connected to this section at different time. The transmission properties of power lines in different regions also have great differences. The influence on a carrier signal due to the factors above depends on the signal frequency. For current PLC technology, carrier signals with a fixed frequency are used. When receiving, the PLC signals will first be amplified by a preamplifier, filtered by a bandpass filter and then output to a demodulator for demodulation.
Following problems in current PLC technology were found during this invention: the processing method and device for the power line carrier signals in current PLC technology is only suitable for carrier signals with fixed frequency, which may not meet the demand of the current PLC.